The present invention relates to a yarn threading apparatus adapted for threading a yarn onto a yarn treatment device, such as the heating and cooling plates of a yarn false twist crimping machine.
U.S. Pat. No. 3,930,292 to Schippers et al discloses an apparatus for threading a yarn onto a yarn treatment apparatus which comprises one or more rotatable heated rollers. This known apparatus comprises a tube through which the yarn is initially conveyed by an airstream flowing in the tube, and the tube includes a longitudinal slot which permits the yarn to exit from the tube after it has passed around the rollers. More particularly, the tube is curved and the slot is directed toward the center of the curvature. As a result, this known device is not suitable for threading a yarn onto a stationary yarn guide device, such as for example, the heating and cooling plates of a yarn false twist crimping machine.
It is accordingly an object of the present invention to provide a yarn threading apparatus which offers new uses, which requires little air, and which maintains the yarn safely within the entire tube length during the initial portion of the threading operation.